The present invention relates generally to an improved structure of a planar heat pipe and, more particularly, to a planar heat pipe used in a computer central processing unit or other electronic heat generating device. The planar heat pipe has high thermal conductivity to dissipate effectively dissipate heat generated by the computer central processing unit or the electronic heat generating device, such that the heat generating device can operate under a uniform temperature.
The development of the computer information technology greatly advances of the designs in the computer related field. For the conventional computer, the operation speed is relatively slow, and the cooling device with a fin-type heat sink and a cooling fan is sufficient. Recently, the clock pulse of the central processing unit has exceeded 1 GHz or even 3 GHz. As the heat generated by the central processing unit is proportional to the clock pulse. The conventional cooling device, being restricted by the limited space within the enclosure of the central processing unit, cannot effectively dissipate the increasing heat generated by the higher operation speed.
FIG. 1 shows a conventional planar heat pipe cooling device. As shown in FIG. 1, the cooling device comprises a heat pipe 10a, a heat sink 20a and a cooling fan 30a. The heat pipe 10a includes a planar heat pipe, in which a wick structure 11a is formed and a working fluid is injected. The heat sink 20a, such as an aluminum pressed heat sink, is installed on the heat pipe 10a. The heat sink 20a includes a plurality of separate heat dissipating fins 21a, between which air circulating channels 22a are formed. By this structure, air blown from the cooling fan 30 is guided into the air circulating channels 22a of the heat sink 20a, such that heat generated by the electronic product such as central processing unit can be dissipated to the external environment.
The conventional planar heat pipe cooling device has the following drawbacks. Firstly, as the air flow blown by the cooling fan 30a has a spiral form. When such air is directed into the channels 22a of the heat sink 20a, turbulence is easily generated. Therefore, air flow cannot be directed to the root of the heat dissipating fins 21a, the heat dissipation efficiency cannot be properly enhanced.
Secondly, the above cooling device uses heat dissipating paste to coat and combine the planar heat pipe 10a and the heat sink 20a. The heat conductivity is affected by the heat dissipating paste.
Therefore, there exist inconvenience and drawbacks for practically application of the above conventional planar heat pipe structure. There is thus a substantial need to provide an improved structure of a planar heat pip heat pipe that resolves the above drawbacks and can be used more conveniently and practically.